Diseases of the Larynx Practice Questions

Q: Respiratory compromise is typically seen in which condition?

Bilateral recurrent laryngeal nerve palsy. **Explanation:** The primary function of the **Recurrent Laryngeal Nerve (RLN)** is to supply all intrinsic muscles of the larynx except the cricothyroid. Crucially, it supplies the **posterior cricoarytenoid (PCA)**, which is the sole abductor of the vocal cords. **1. Why Option A is Correct:** In **Bilateral Recurrent Laryngeal Nerve Palsy**, both vocal cords lose their ability to abduct. According to **Semon’s Law**, the abductor fibers are more vulnerable than adductor fibers. Consequently, the cords assume a **median or paramedian position**. This significantly narrows the glottic chink, leading to acute **respiratory compromise** and inspiratory stridor, often necessitating an emergency tracheostomy. **2. Why the Incorrect Options are Wrong:** * **Option B:** In combined palsy (Superior + Recurrent), the cricothyroid (tenser) is also paralyzed. This results in a "cadaveric" position (mid-way between midline and lateral). While the voice is very breathy, the airway remains adequate. * **Option C & D:** In **Unilateral RLN Palsy** (complete or incomplete), the unaffected vocal cord can usually compensate by crossing the midline to meet the paralyzed cord. While this causes hoarseness of voice, the airway remains patent, and there is no respiratory distress. **High-Yield Clinical Pearls for NEET-PG:** * **Semon’s Law:** In progressive lesions of the RLN, abductor fibers are damaged before adductor fibers. * **Wagner and Grossman Theory:** The cricothyroid muscle (supplied by the Superior Laryngeal Nerve) keeps the cord in a paramedian position even if the RLN is out. * **Most common cause of Bilateral RLN Palsy:** Thyroid surgery (total thyroidectomy). * **Management:** Emergency tracheostomy for airway; later, lateralization of the cord (e.g., Woodman’s operation).

Q: Topical mitomycin-C is used in which of the following conditions?

Laryngotracheal stenosis. **Explanation:** **Laryngotracheal Stenosis (Correct Answer):** Mitomycin-C (MMC) is a potent fibroblast inhibitor derived from *Streptomyces caespitosus*. In ENT, it is used topically (typically 0.4 mg/ml) to prevent the formation of excessive scar tissue. In **Laryngotracheal Stenosis (LTS)** and subglottic stenosis, it is applied following endoscopic dilation or laser excision. By inhibiting DNA synthesis and fibroblast proliferation, it reduces the deposition of collagen, thereby preventing restenosis and improving the long-term patency of the airway. **Analysis of Incorrect Options:** * **Sturge-Weber Syndrome:** This is a neurocutaneous disorder characterized by port-wine stains and leptomeningeal angiomas. Management involves laser therapy for skin lesions and anticonvulsants; MMC has no role here. * **Endoscopic Angiofibroma:** Juvenile Nasopharyngeal Angiofibroma (JNA) is a highly vascular tumor. The mainstay of treatment is preoperative embolization followed by surgical excision. MMC does not address the vascular nature of this tumor. * **Skull Base Osteomyelitis:** This is a severe infection (usually Pseudomonas) requiring long-term intravenous antibiotics and surgical debridement. MMC, an antiproliferative agent, is contraindicated in active infections as it may impair healing. **High-Yield Clinical Pearls for NEET-PG:** * **Other ENT uses of Mitomycin-C:** Prevention of synechiae after Functional Endoscopic Sinus Surgery (FESS), maintaining patency of choanal atresia repair, and preventing closure of a myringotomy (prolonging tube patency). * **Mechanism:** It acts as an alkylating agent that cross-links DNA. * **Application:** It is applied topically via a soaked cottonoid for approximately 2–5 minutes. * **LTS Grading:** Remember the **Cotton-Myer Classification** for grading the severity of subglottic stenosis based on the percentage of lumen reduction.

Q: In the Nodal "N" staging of laryngeal carcinoma, extranodal invasion is indicated by which category?

N3B. **Explanation:** The staging of laryngeal carcinoma follows the **AJCC 8th Edition** TNM classification. The 8th edition introduced a significant change by incorporating **Extranodal Extension (ENE)** into the "N" staging, as it is a major prognostic indicator for poor outcomes. **1. Why N3b is correct:** According to the AJCC 8th Edition, the **N3** category is subdivided based on size and ENE: * **N3a:** Metastasis in a lymph node larger than 6 cm in greatest dimension, but **without** extranodal extension (ENE-). * **N3b:** Metastasis in any node(s) with **clinically overt extranodal extension (ENE+)**. This means if ENE is present, the size or number of nodes no longer dictates the stage; it automatically becomes N3b. **2. Why other options are incorrect:** * **N2c:** Represents bilateral or contralateral lymph node metastasis, none larger than 6 cm, and without ENE. * **N3a:** As mentioned, this is a large node (>6 cm) but specifically lacks extranodal invasion. * **N3c:** This category does not exist in the current AJCC TNM staging for laryngeal cancer. **High-Yield Clinical Pearls for NEET-PG:** * **ENE Definition:** Extension of tumor through the lymph node capsule into the surrounding connective tissue. * **Clinical ENE:** Suggested by skin involvement, fixation to adjacent structures (muscles/vessels), or nerve invasion. * **TNM 7th vs 8th:** In the 7th edition, N3 was simply any node >6 cm. The 8th edition added ENE to refine prognostic accuracy. * **Most common site:** The most common site for laryngeal cancer is the **Glottis**, but **Supraglottic** cancers have a higher rate of nodal metastasis due to rich lymphatic drainage.

Q: What is true about multiple papillomatosis?

It is a premalignant condition.. **Explanation:** **Multiple Papillomatosis** (specifically Juvenile Laryngeal Papillomatosis) refers to the development of multiple benign squamous papillomas in the respiratory tract [1]. **1. Why Option C is Correct:** While individual papillomas are benign, multiple papillomatosis is considered a **premalignant condition**. Although the risk of spontaneous malignant transformation into squamous cell carcinoma is low (approx. 1–3%), it is a well-documented complication, especially in cases with long-standing disease or those exposed to co-carcinogens [1]. **2. Why the other options are incorrect:** * **Option A:** The causative agent is the **Human Papillomavirus (HPV)**, specifically genotypes **6 and 11**, not Herpes Simplex Virus. * **Option B:** **Radiotherapy is contraindicated.** It is not the treatment of choice because it significantly increases the risk of malignant transformation into an aggressive squamous cell carcinoma. The standard treatment is surgical debulking (CO2 laser or microdebrider). * **Option D:** Multiple papillomatosis is most common in **children (under age 5)** [1], often acquired during childbirth via an infected birth canal. A second peak occurs in adulthood (20–40 years), but the "multiple" juvenile form is classically a pediatric diagnosis. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of symptoms:** Hoarseness of voice, chronic cough, and stridor. * **Histology:** Finger-like projections of non-keratinized stratified squamous epithelium with a central fibrovascular core and characteristic **koilocytic changes** [1]. * **Adjuvant therapy:** Cidofovir (antiviral) or Interferon-alpha may be used in refractory cases. * **Prevention:** The HPV vaccine (Gardasil) is effective in reducing the incidence of maternal transmission. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Head and Neck, pp. 745-746.

Q: A 65-year-old man presented with vocal cord palsy. He has a history of pan chewing since childhood. On examination, the abducting function of his vocal cord is impaired. Which nerve is most likely affected?

Recurrent laryngeal nerve. ### Explanation The correct answer is **Recurrent Laryngeal Nerve (RLN)**. **1. Why the Recurrent Laryngeal Nerve is correct:** The intrinsic muscles of the larynx are responsible for the abduction and adduction of the vocal cords. All intrinsic muscles of the larynx—except for the cricothyroid—are supplied by the **Recurrent Laryngeal Nerve**. Specifically, the **Posterior Cricoarytenoid (PCA)** is the sole abductor of the vocal cords (often called the "safety muscle of the larynx"). Therefore, any impairment in the abducting function of the vocal cord directly indicates a lesion or palsy of the RLN. **2. Why the other options are incorrect:** * **External Laryngeal Nerve:** This nerve supplies only the **Cricothyroid muscle**, which acts as a tensor of the vocal cords. Damage to this nerve leads to a loss of pitch and a "husky" voice, but not a loss of abduction. * **Mandibular Nerve:** This is a branch of the Trigeminal nerve (CN V) and supplies the muscles of mastication and sensory innervation to the lower face. It has no role in vocal cord movement. * **Vagus Nerve:** While the RLN is a branch of the Vagus nerve (CN X), a high vagal lesion would typically present with additional symptoms like dysphagia (due to pharyngeal branch involvement) or palatal palsy. The specific loss of abduction is the hallmark of its distal branch, the RLN. **3. High-Yield Clinical Pearls for NEET-PG:** * **Posterior Cricoarytenoid (PCA):** The only **abductor** (Safety muscle). * **Lateral Cricoarytenoid (LCA):** The primary **adductor**. * **Semon’s Law:** In progressive lesions of the RLN, abductor fibers are more susceptible and are paralyzed first compared to adductor fibers. * **Left RLN** is more commonly involved in vocal cord palsy because of its longer intrathoracic course (looping around the arch of the aorta), making it vulnerable to mediastinal pathologies (e.g., lung cancer, mitral stenosis/Ortner’s syndrome).

Q: Maintenance of airway during laryngectomy in a patient with carcinoma of the larynx is best done by which of the following?

Tracheostomy. **Explanation:** In the surgical management of carcinoma of the larynx (Total Laryngectomy), the primary goal is the complete removal of the larynx, which results in a permanent separation of the digestive and respiratory tracts. **Why Tracheostomy is the Correct Choice:** During a laryngectomy, the larynx is excised, and the distal trachea is brought out to the skin of the neck to create a **permanent end-stoma**. A tracheostomy (specifically, a "low" tracheostomy or a per-operative tracheal intubation through a stoma) is the only definitive way to maintain a secure airway once the upper airway (larynx) is removed. It ensures bypass of the surgical site, prevents aspiration of blood/secretions, and allows the surgeon to work unimpeded in the neck. **Why Other Options are Incorrect:** * **Laryngeal Mask Airway (LMA):** This is a supraglottic airway device that sits above the vocal cords. Since the larynx is being surgically removed, an LMA cannot maintain an airway and would obstruct the surgical field. * **Laryngeal Tube:** Similar to the LMA, this is a supraglottic device. It is contraindicated in laryngeal surgery as it occupies the space that needs to be dissected. * **Combitube:** This is a double-lumen emergency airway device usually inserted blindly. It is entirely inappropriate for elective major head and neck surgery where a secure, definitive airway is required. **Clinical Pearls for NEET-PG:** * **Total Laryngectomy** results in a **permanent tracheostome**; the patient becomes a "total neck breather." * In cases of laryngeal mass with impending airway obstruction, a **"high" tracheostomy** is avoided to prevent tumor seeding (stomal recurrence). * **Post-laryngectomy:** The patient can no longer perform the Valsalva maneuver effectively due to the loss of the glottic closure reflex.

Q: Which anatomical landmark is used to determine the level of tracheostomy?

Isthmus of the thyroid. **Explanation:** The **isthmus of the thyroid gland** is the primary anatomical landmark used to determine the level of a tracheostomy. In a standard elective tracheostomy, the isthmus typically overlies the second, third, and fourth tracheal rings. To access the trachea, the surgeon must either retract the isthmus superiorly/inferiorly or divide it between clamps to expose the underlying tracheal rings. * **Why Option B is correct:** The isthmus serves as the "gatekeeper" to the trachea. Its identification is crucial for surgical orientation. Once the isthmus is managed, the incision is usually made in the **2nd and 3rd or 3rd and 4th tracheal rings**. * **Why Option A is wrong:** The **Cricoid cartilage** is the landmark for a **Cricothyroidotomy** (emergency airway), not a tracheostomy. Performing a tracheostomy at or above the cricoid is contraindicated as it leads to subglottic stenosis. * **Why Options C & D are wrong:** While the 2nd and 3rd tracheal rings are the *site* where the tracheal window is created, they are not the *landmark* used to navigate the procedure. The thyroid isthmus must be identified first to safely reach these rings. **High-Yield Clinical Pearls for NEET-PG:** 1. **Level of Tracheostomy:** High (1st ring - avoided), Mid (2nd, 3rd, 4th rings - **Preferred**), Low (below 4th ring - avoided due to risk of injury to the innominate artery). 2. **Emergency Airway:** Cricothyroidotomy is the procedure of choice for immediate airway obstruction. 3. **Most common complication (Immediate):** Hemorrhage (from thyroid vessels or anterior jugular veins). 4. **Most common late complication:** Tracheal stenosis.

Question 1

Respiratory compromise is typically seen in which condition?

Accepted Answer

Bilateral recurrent laryngeal nerve palsy

Answer

Superior and recurrent laryngeal nerve palsy

Answer

Incomplete unilateral recurrent laryngeal nerve palsy

Answer

Complete unilateral recurrent laryngeal nerve palsy

Question 2

Topical mitomycin-C is used in which of the following conditions?

Accepted Answer

Laryngotracheal stenosis

Answer

Sturge-Weber syndrome

Answer

Endoscopic angiofibroma

Answer

Skull base osteomyelitis

Question 3

In tracheostomy, the entry into the trachea is through which anatomical structures?

Accepted Answer

Second and third tracheal rings

Answer

Cricoid cartilage

Answer

First tracheal ring

Answer

Fourth and fifth tracheal rings

Question 4

Which of the following treatments is indicated for Juvenile Onset Recurrent Respiratory Papillomatosis?

Accepted Answer

Bevacizumab

Answer

Aerosol Cidofovir

Answer

Interferon Beta

Answer

Steroids

Question 5

In the Nodal "N" staging of laryngeal carcinoma, extranodal invasion is indicated by which category?

Accepted Answer

N3B

Answer

N2C

Answer

N3A

Answer

N3C

Question 6

What is true about multiple papillomatosis?

Accepted Answer

It is a premalignant condition.

Answer

Herpes Simplex Virus is the causative agent.

Answer

Radiotherapy is the treatment of choice.

Answer

It is more common in individuals aged 15 to 33 years.

Question 7

A 65-year-old man presented with vocal cord palsy. He has a history of pan chewing since childhood. On examination, the abducting function of his vocal cord is impaired. Which nerve is most likely affected?

Accepted Answer

Recurrent laryngeal nerve

Answer

External laryngeal nerve

Answer

Mandibular nerve

Answer

Vagus nerve

Question 8

An end tracheostomy is performed in patients undergoing which of the following procedures?

Accepted Answer

Laryngectomy

Answer

Laryngofissure surgery

Answer

Oropharyngeal tumor resection

Answer

Surgical correction of obstructive sleep apnea with stridor

Question 9

Maintenance of airway during laryngectomy in a patient with carcinoma of the larynx is best done by which of the following?

Accepted Answer

Tracheostomy

Answer

Laryngeal mask airway

Answer

Laryngeal tube

Answer

Combitube

Question 10

Which anatomical landmark is used to determine the level of tracheostomy?

Accepted Answer

Isthmus of the thyroid

Answer

Cricoid cartilage

Answer

Second tracheal ring

Answer

Third tracheal ring

Diseases of the Larynx — MCQs

Diseases of the Larynx — MCQs

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